Clinical outcomes of immediate/early loading of dental implants. A literature review of recent controlled prospective clinical studies

Clinical performance of narrow-diameter titanium-zirconium implants in immediately loaded fixed full-arch prostheses: a 2-year clinical study

Objectives

The aim of this study was to evaluate the outcomes of immediate fixed full-arch prostheses supported by axial or tilted narrow-diameter Ti-Zr implants (3.3 mm) (Roxolid®, Institut Straumann® AG, Basel, Switzerland) (NDIs) in combination with standard-diameter implants up to 2 years’ follow-up.

Materials and methods

The study was conducted at Kocaeli University Faculty of Dentistry from 2016 to 2018. 37 jaws of 28 patients with an average age of 52 years were rehabilitated with fixed full-arch prostheses supported by 179 implants. Cumulative survival rate (CSR), implant success, marginal bone loss (MBL), and prosthetic survival rate as well as complications were analyzed.

Results

Total CSR of 99.4% and 98.5% for all and narrow implants respectively have been observed at 2 years’ follow-up. No prosthesis failures were observed, yielding a cumulative prosthetic survival rate of 100%. The NDIs achieved 0.63 mm MBL at 1 year and 1.02 mm at 2 years. The mean MBL at 1 year was 0.51 mm (mandible 0.63 mm/maxilla 0.41 mm) and 0.73 mm (mandible 0.90 mm/maxilla 0.43 mm) at 2 years. Both implant angulation and loading protocol did not influence the MBL.

Conclusions

The combination of narrow-diameter implants with standard-diameter implants in immediate fixed full-arch rehabilitation has a good prognosis to become a new standard of care for severely atrophic jaws.

Clinical relevance

The use of narrow-diameter implants in fixed full-arch rehabilitations in atrophic ridges would be a successful and predictable treatment approach.

Methodological quality and risk of bias of systematic reviews about loading time of multiple dental implants in totally or partially edentulous patients: An umbrella systematic review

BACKGROUND

There are several systematic reviews of multiple implant loading techniques, but results are conflicting.

AIM

To perform an umbrella review on methodological quality of systematic reviews about techniques for loading multiple dental implants.

MATERIAL AND METHODS

MEDLINE (PubMed) and Scopus were searched up to December 31, 2019. Unpublished literature was searched through OpenGray and references of included articles were manually verified. Eligibility criteria were: articles had to (1) be about multiple dental implants; (2) mention the moment of loading; (3) be a systematic review. Two independent reviewers participated in the entire process. Qualitative description of included studies as well as methodological quality measurement and risk of bias through AMSTAR and ROBIS were performed.

RESULTS

21 reviews were included. Thirteen stated that there was a similarity between loading techniques, two did not affirm which one was more appropriate and six mentioned that conventional technique was better. Eight papers were classified as high risk of bias, twelve as low and one as uncertain risk.

CONCLUSION

When evaluating only studies with a low risk of bias, there are no significant differences in implant loading time.

Immediate versus delayed temporization at posterior single implant sites: A randomized controlled trial

AIMS

We conducted a randomized controlled trial to assess the clinical outcomes of two loading protocols involving either immediate or delayed prosthetic temporization of single implants placed at posterior, healed sites.

MATERIALS AND METHODS

Forty-nine patients in need of single implants at premolar or molar sites were randomized to receive a temporary crown either immediately after implant placement or 3 months later. Randomization was stratified by sex, implant location (premolar/molar) and arch (maxilla/mandible). Final implant screw-retained zirconia crowns with angulated screw channels were delivered at 5 months after surgery. Radiographic bone levels (primary outcome), peri-implant mucosal margin levels and peri-implant probing depths were recorded at baseline, 6 and 12 months after surgery.

RESULTS

Both treatment arms showed similar patterns of soft tissue and bone re-modelling from the implant platform over 12 months [mean bone level change 1.6 mm (SD 1.0 mm) in the delayed, and 1.2 mm (SD 1.3 mm) in the immediate temporization group], with the majority of changes occurring within the first 6 months.

CONCLUSIONS

Immediate or delayed temporization of single implants placed at posterior healed sites resulted in largely similar 1-year outcomes with respect to peri-implant bone levels and soft tissue changes.

Immediate nonfunctional loading of implants placed simultaneously using computer-guided flapless maxillary crestal sinus augmentation with bone morphogenetic protein-2/collagen matrix

BACKGROUND

Immediate loading has shown positive results for total, partial, or single edentulism. The effects of BMP-2 addition to graft materials on bone formation and implant stability in the early stages of healing have rarely been studied, especially in patients with severely atrophic maxillae.

PURPOSE

To evaluate the effects of simultaneously placed immediate non-functional loaded implants and bone morphogenetic protein-2 (BMP-2)-loaded Bio-Oss collagen, on bone formation and implant stability during the early healing stages of patients with a severely atrophic posterior maxilla using crestal approach.

MATERIALS AND METHODS

Thirty-three cases presenting posterior maxillary residual alveolar bone height of 1-3 mm were evaluated. Flapless crestal sinus augmentation surgery was performed using BMP-2-loaded Bio-Oss collagen, with non-functional implants immediately loaded after surgery. The bone height was assessed using preoperative and postoperative cone beam computed tomography (CBCT). Bone density of the sinus graft sites and implant stability (after 3 months) were evaluated using postoperative CBCT scans and Periotest, respectively. The periodontal parameters and marginal bone loss around the implant were checked after 37.3 months of final prosthesis.

RESULTS

The survival rate of the implants was 100% and the gingiva around the implants remained healthy. All implants remained integrated, and all sinus grafts showed radiographic bone formation. The results indicated high level of bone density and good implant stability, showing minimal marginal bone loss after 37.3 months.

CONCLUSION

This technique could be used in the posterior maxillary region exhibiting poor bone quantity.

Implant-Supported PMMA Monolithic Full-Arch Rehabilitation with Surgical Computer-Planned Guide and Immediate Provisional: A Case Report with One Year Follow-Up

The aim of this case report is to describe the surgical and prosthetic procedures to achieve maxillary and mandibular implant-supported PMMA monolithic full-arch rehabilitation (PMFR) with surgical computer-planned guide and immediate provisional. In such cases, the correct planning of dental implants' position, length, and diameter and the prosthetic phases via computer-aided design are very important to achieve good aesthetic and functional long-lasting results.

Prospective multicenter non-randomized controlled study on intraosseous stability and healing period for dental implants in the posterior region

Background

A current implant body surface was treated with “rough processing” by sandblasting and acid etching for the purposes of obtaining more reliable osseointegration and shortening the treatment period. Various reports have examined the healing period with the use of these implant bodies, but a consensus opinion has not yet been obtained. The purpose of this study is to evaluate the relationship between insertion torque (IT) and implant stability quotient (ISQ) at implant treatment using the current rough-surfaced implant. We evaluated the implant treatment sites with ISQ values, IT values, and voxel values.

Methods

Participants in this study comprised 26 patients (10 males, 16 females; mean age, 55.5 years) who received posterior region dental implants at Tokyo Dental College Hospital or Fukuoka Dental College Hospital. For all participants, pretreatment computed tomography and determination of bone quality from voxel values were performed. Thirty-two implant bodies were inserted into the posterior region, and insertion torque was measured. ISQ was also measured at 0, 2, 4, 6, 8, and 12 weeks postoperatively.

Results

Eight implant bodies in the maxilla and 24 in the mandible were inserted. All ISQ values increased, exceeding 60 by 6 weeks postoperatively. For insertion torque < 30 N cm, ISQ increased significantly after 8 weeks. For ≥ 30 N cm, the ratio at which high ISQ values appeared increased significantly after 6 weeks. Compared with the treatment area with insertion torque < 40 N cm, the treatment area ≥ 40 N cm showed a significantly higher voxel value.

Conclusions

No significant relationship was found between the insertion torque value and the ISQ value. Also, it was suggested that the ISQ value was considered to be an important indicator for observing the treatment state of the implant.

Increasing the Stability of Dental Implants: the Concept of Osseodensification

One of the most important factors that affect osseointegration is the primary stability of the implant. Dental implants inserted at the posterior region of the maxilla exhibit the lowest success rates as the low density bone in this area often jeopardize rigid fixation of the implant. Many surgical techniques have been developed to increase the primary stability of an implant placed in low density bone, such as bicortical fixation of the implant, undersized preparation of the implant bed and bone condensation by the use of osteotomes. A new promising technique, named osseodensification, has been recently developed that creates an autograft layer of condensed bone at the periphery of the implant bed by the aid of specially designed burs rotating in a clockwise and anti-clockwise direction. The purpose of this review is to emphasize that implant primary stability is strongly influenced by the surgical technique, to quote and briefly analyse the various surgical procedures laying weight to osseodensification procedure.

Success rate and strength of osseointegration of immediately loaded UV-photofunctionalized implants in a rat model

STATEMENT OF PROBLEM

Despite its clinical benefits, the immediate loading protocol might have a higher risk of implant failure than the regular protocol. Ultraviolet (UV) photofunctionalization is a novel surface enhancement technique for dental implants. However, the effect of photofunctionalization under loading conditions is unclear.

PURPOSE

The purpose of this animal study was to evaluate the effect of photofunctionalization on the biomechanical quality and strength of osseointegration under loaded conditions in a rat model.

MATERIAL AND METHODS

Untreated and photofunctionalized, acid-etched titanium implants were placed into rat femurs. The implants were immediately loaded with 0.46 N of constant lateral force. The implant positions were evaluated after 2 weeks of healing. The strength of osseointegration was evaluated by measuring the bone-implant interfacial breakdown point during biomechanical push-in testing.

RESULTS

Photofunctionalization induced hydrophilic surfaces on the implants. Osseointegration was successful in 28.6% of untreated implants and 100% of photofunctionalized implants. The strength of osseointegration in successful implants was 2.4 times higher in photofunctionalized implants than in untreated implants. The degree of tilt of untreated implants toward the origin of force was twice that of photofunctionalized implants.

CONCLUSIONS

Within the limit of an animal model, photofunctionalization significantly increased the success of osseointegration and prevented implant tilt. Even for the implants that underwent successful osseointegration, the strength of osseointegration was significantly higher for photofunctionalized implants than for untreated implants. Further experiments are warranted to determine the effectiveness of photofunctionalization on immediately loaded dental implants.

Long-Term Outcomes of Early Loading of Straumann Implant-Supported Fixed Segmented Bridgeworks in Edentulous Maxillae: A 10-Year Prospective Study

BACKGROUND

There have been few studies investigating the long-term outcome of early-loaded implants with segmented bridgeworks on fully edentulous maxillae.

PURPOSE

To evaluate the long-term predictability of early-loaded Straumann implant-supported fixed segmented bridgeworks in edentulous maxillae.

MATERIAL AND METHODS

Ninety-one implants were placed in 12 patients with edentulous maxillae. After a healing period of 6 weeks, the abutments were tightened followed by cementing of fixed full-arch prostheses. The patients were recalled after 1, 3, 5, and 10 years of loading for clinical evaluation. Implant success rate, peri-implant soft tissue condition, technical complications, marginal bone loss and patients' satisfaction was assessed.

RESULTS

Eleven of the 12 patients attended the 10-year follow-up. Two implants were lost. The implant success rate was 97.6% at implant level and 81.8% at patient level. The mean marginal bone loss was found to be 0.41 ± 0.55mm, 0.53 ± 0.43mm, 0.68 ± 0.76 mm and 1.01 ± 0.85 mm at the 1, 3, 5, and 10-year follow-up respectively. None of the 11 patients showed a modified plaque index (mPLI) or modified bleeding index (mBI) of 3. Only one patient was found to have pocket probing depth (PPD) exceeding 3 mm. Peri-implantitis was found around one of the implants in a patient after 4 years of loading. The success rate of prostheses was 55.3% at prosthesis level and 27.3% at patient level. The most common technical complication of the prostheses was chipping of the ceramic veneer. Damaged veneers were observed in five patients. Other complications were loss of retention and abutment loosening.

CONCLUSION

Early loading of Straumann SLA implants for support of full-arch segmented bridgeworks represents a viable therapy for the fully edentulous maxillae in the long term. High success rate of implants, acceptable peri-implant soft tissue condition and excellent patient satisfaction can be achieved, while technical complications of prostheses are common.

Efficacy of standard (SLA) and modified sandblasted and acid-etched (SLActive) dental implants in promoting immediate and/or early occlusal loading protocols: a systematic review of prospective studies

OBJECTIVE

To assess the survival percentage, clinical and radiographic outcomes of sandblasted and acid-etched (SLA) dental implants and its modified surface (SLActive) in protocols involving immediate and early occlusal loading.

METHODS

MEDLINE, EMBASE and the Cochrane Oral Health Group's Trials Register CENTRAL were searched in duplicate up to, and including, June 2013 to include randomised controlled trials (RCTs) and prospective observational studies of at least 6-month duration published in all languages. Studies limited to patients treated with SLA and/or SLActive implants involving a treatment protocol describing immediate and early loading of these implants were eligible for inclusion. Data on clinical and/or radiographic outcomes following implant placement were considered for inclusion.

RESULTS

Of the 447 potentially eligible publications identified by the search strategy, seven RCTs comprising a total of 853 implants (8% titanium plasma-sprayed, 41.5% SLA and 50.5% SLActive) and 12 prospective observational studies including 1394 SLA and 145 SLActive implants were included in this review. According to the Cochrane Collaboration's tool for assessing risk of bias, one of the studies was considered to be at a low risk of bias, whereas the remaining studies were considered to be at an unclear risk. Regarding the observational studies, all of them presented a medium methodological quality based on the Modified Newcastle-Ottawa scale. There were no significant differences reported in the studies in relation to implant loss or clinical parameters between the immediate/early loading and delayed loading protocols. Overall, 95% of SLA and 97% of SLActive implants still survive at the end of follow-up.

CONCLUSIONS

Despite of the positive findings achieved by the included studies, few RCTs were available for analysis for SLActive implants. Study heterogeneity, scarcity of data and the lack of pooled estimates represent a limitation between studies' comparisons and should be considered when interpreting the present findings.

Prospective, 1-year observational study of double-threaded tapered body dental implants with immediate loading

STATEMENT OF PROBLEM

Unlike conventional loading protocols, the immediate loading of single implants has not been fully investigated.

PURPOSE

The purpose of this study was to assess the prosthetic and esthetic periimplant mucosal outcomes of immediately restored dental implants during a 1-year follow-up.

MATERIAL AND METHODS

Twenty participants meeting the established inclusion criteria received double-threaded, tapered body dental implants (SuperLine; Dentium). Implants were placed and stabilized at a minimum of 35 Ncm of torque and restored immediately after the surgery with interim restorations. These were replaced with definitive restorations 6 months after implant placement. Clinical measurements at each visit included resonance frequency analysis, the evaluation of the participants' oral health (gingival and plaque indices), and the esthetic outcome of the interim or definitive restoration.

RESULTS

Implants placed in this clinical study had a 100% success rate. The oral health and esthetic outcomes were favorable for all participants.

CONCLUSIONS

Double-threaded, tapered body dental implants that were placed and immediately restored with fixed interim prostheses and with definitive prostheses after 6 months remained stable and functional after 1 year.

Multiscale analyses of the bone-implant interface

Implants placed with high insertion torque (IT) typically exhibit primary stability, which enables early loading. Whether high IT has a negative impact on peri-implant bone health, however, remains to be determined. The purpose of this study was to ascertain how peri-implant bone responds to strains and stresses created when implants are placed with low and high IT. Titanium micro-implants were inserted into murine femurs with low and high IT using torque values that were scaled to approximate those used to place clinically sized implants. Torque created in peri-implant tissues a distribution and magnitude of strains, which were calculated through finite element modeling. Stiffness tests quantified primary and secondary implant stability. At multiple time points, molecular, cellular, and histomorphometric analyses were performed to quantitatively determine the effect of high and low strains on apoptosis, mineralization, resorption, and collagen matrix deposition in peri-implant bone. Preparation of an osteotomy results in a narrow zone of dead and dying osteocytes in peri-implant bone that is not significantly enlarged in response to implants placed with low IT. Placing implants with high IT more than doubles this zone of dead and dying osteocytes. As a result, peri-implant bone develops micro-fractures, bone resorption is increased, and bone formation is decreased. Using high IT to place an implant creates high interfacial stress and strain that are associated with damage to peri-implant bone and therefore should be avoided to best preserve the viability of this tissue.

Influence of surgical and prosthetic techniques on marginal bone loss around titanium implants. Part I: immediate loading in fresh extraction sockets

PURPOSE

Delayed placement of implant abutments has been associated with peri-implant marginal bone loss; however, long-term results obtained by modifying surgical and prosthetic techniques after implant placement are still lacking. This study aimed to evaluate the marginal bone loss around titanium implants placed in fresh extraction sockets using two loading protocols after a 5-year follow-up period.

MATERIAL AND METHODS

A total of 36 patients received 40 titanium implants (Astra Tech) intended for single-tooth replacement. Implants were immediately placed into fresh extraction sockets using either a one-stage (immediate loading by placing an interim prosthesis into functional occlusion) or a two-stage prosthetic loading protocol (insertion of abutments after 8 weeks of healing time). Marginal bone levels relative to the implant reference point were evaluated at four time intervals using intraoral radiographs: at time of implant placement, and 1, 3, and 5 years after implant placement. Measurements were obtained from mesial and distal surfaces of each implant (α = 0.05).

RESULTS

One-stage immediate implant placement into fresh extraction sockets resulted in a significant reduction in marginal bone loss (p < 0.002) compared to the traditional two-stage technique. Whereas mesial surfaces remained stable for the 5-year observation period, significant marginal bone loss was observed on distal surfaces of implants after cementation of interim prostheses (p < 0.007) and after 12 months (p < 0.034).

CONCLUSIONS

Within the limitations of this study, immediate loading of implants placed into fresh extraction sockets reduced marginal bone loss and did not compromise the success rate of the restorations.

Interventions for replacing missing teeth: different times for loading dental implants

BACKGROUND

To minimise the risk of implant failures after their placement, dental implants are kept load-free for 3 to 8 months to establish osseointegration (conventional loading). It would be beneficial if the healing period could be shortened without jeopardising implant success. Nowadays implants are loaded early and even immediately and it would be useful to know whether there is a difference in success rates between immediately and early loaded implants compared with conventionally loaded implants.

OBJECTIVES

To evaluate the effects of (1) immediate (within 1 week), early (between 1 week and 2 months), and conventional (after 2 months) loading of osseointegrated implants; (2) immediate occlusal versus non-occlusal loading and early occlusal versus non-occlusal loading; (3) direct loading versus progressive loading immediately, early and conventionally.

SEARCH METHODS

The following electronic databases were searched: the Cochrane Oral Health Group's Trials Register (to 8 June 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2012, Issue 4), MEDLINE via OVID (1946 to 8 June 2012) and EMBASE via OVID (1980 to 8 June 2012). Authors of identified trials were contacted to find unpublished randomised controlled trials (RCTs). There were no restrictions regarding language or date of publication.

SELECTION CRITERIA

All RCTs of root-form osseointegrated dental implants, having a follow-up of 4 months to 1 year, comparing the same implant type immediately, early or conventionally loaded, occlusally or non-occlusally loaded, or progressively loaded or not. Outcome measures were: prosthesis and implant failures and radiographic marginal bone level changes.

DATA COLLECTION AND ANALYSIS

Data were independently extracted, in duplicate, by at least two review authors. Trial authors were contacted for missing information. Risk of bias was assessed for each trial by at least two review authors, and data were extracted independently, and in duplicate. Results were combined using fixed-effect models with mean differences (MD) for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CI). A summary of findings table of the main findings was constructed.

MAIN RESULTS

Forty-five RCTs were identified and, from these, 26 trials including a total of 1217 participants and 2120 implants were included. Three trials were at low risk of bias, 12 were at high risk of bias and for the remaining 11 the risk of bias was unclear. In nine of the included studies there were no prosthetic failures within the first year, with no implant failures in 7 studies and the mean rate of implant failure in all 26 trials was a low 2.5%. From 15 RCTs comparing immediate with convential loading there was no evidence of a difference in either prosthesis failure (RR 1.87; 95% CI 0.70 to 5.01; 8 trials) or implant failure (RR 1.65; 95% CI 0.68 to 3.98; 10 trials) in the first year, but there is some evidence of a small reduction in bone loss favouring immediate loading (MD -0.10 mm; 95% CI -0.20 to -0.01; P = 0.03; 9 trials), with some heterogeneity (Tau² = 0.01; Chi² = 14.37, df = 8 (P = 0.07); I² = 44%). However, this very small difference may not be clinically important. From three RCTs which compared early loading with conventional loading, there is insufficient evidence to determine whether or not there is a clinically important difference in prosthesis failure, implant failure or bone loss. Six RCTs compared immediate and early loading and found insufficient evidence to determine whether or not there is a clinically important difference in prosthesis failure, implant failure or bone loss. From the two trials which compared occlusal loading with non-occlusal loading there is insufficient evidence to determine whether there is a clinically important difference in the outcomes of prosthesis failure, implant failure or bone loss. We did not identify any trials which evaluated progressive loading of implants.

AUTHORS' CONCLUSIONS

Overall there was no convincing evidence of a clinically important difference in prosthesis failure, implant failure, or bone loss associated with different loading times of implants. More well-designed RCTs are needed and should be reported according to the CONSORT guidelines (www.consort-statement.org/).

Methodological quality and descriptive characteristics of prosthodontic-related systematic reviews

Ideally, healthcare systematic reviews (SRs) should be beneficial to practicing professionals in making evidence-based clinical decisions. However, the conclusions drawn from SRs are directly related to the quality of the SR and of the included studies. The aim was to investigate the methodological quality and key descriptive characteristics of SRs published in prosthodontics. Methodological quality was analysed using the Assessment of Multiple Reviews (AMSTAR) tool. Several electronic resources (MEDLINE, EMBASE, Web of Science and American Dental Association's Evidence-based Dentistry website) were searched. In total 106 SRs were located. Key descriptive characteristics and methodological quality features were gathered and assessed, and descriptive and inferential statistical testing performed. Most SRs in this sample originated from the European continent followed by North America. Two to five authors conducted most SRs; the majority was affiliated with academic institutions and had prior experience publishing SRs. The majority of SRs were published in specialty dentistry journals, with implant or implant-related topics, the primary topics of interest for most. According to AMSTAR, most quality aspects were adequately fulfilled by less than half of the reviews. Publication bias and grey literature searches were the most poorly adhered components. Overall, the methodological quality of the prosthodontic-related systematic was deemed limited. Future recommendations would include authors to have prior training in conducting SRs and for journals to include a universal checklist that should be adhered to address all key characteristics of an unbiased SR process.

Comparative evaluation of two types of immediately loaded implants using biomechanical and histomorphometric tests: an animal case study

Introduction. In order to minimize the required time to regain esthetic and function, immediately loaded implants were suggested. The aim of this study was to comparatively evaluate the Nisastan and XIve implants using biomechanical and histomorphometric tests. Materials and Methods. In this experimental study, 6 Nisastan one-piece immediately loaded screw type implant (OPILS) and 6 Xive implants with 3.4 mm diameter and 11 mm long were used. The implants were immediately loaded with temporary coating. After three months, the torque required to break bone-implant contact was measured and was recorded. All implants were extracted with surrounding bone and histologically were evaluated. The data were inputted into the SPSS 11.5 to run student T-test statistical analyses (α = 0.05). Results. The success rates of both types of implants was 100%, and none of them failed due to mobility or bone loss. The mean removal torque value (RTV) was 142.08 and 40 N/Cm for Xive and Nisastan implants, respectively, and their RTVs showed a significant difference between two mentioned implants (P = 0.004). None of the histomorphometric values showed significant differences between the two implants (P > 0.05). Discussion. both systems have the capability to induce osseointegration under immediate loads but that Xive implants showed higher capability for bone contact.

A comparison of biocompatibility and osseointegration of ceramic and titanium implants: an in vivo and in vitro study

This study compared the biocompatibility in vitro and the osseointegration in vivo of zirconium and titanium implants regarding implant surfaces and the bone-implant contacts. The different implant surfaces and the biocompatibility of zirconium versus titanium implants were determined by vitality and cytotoxic tests in vitro. The contact of the osteoblasts to the implant surface was determined by scanning electron microscopy (SEM). The in vivo study for osseointegration was performed in domestic pigs over 4 and 12 weeks. In each animal, 4 zirconium and 4 titanium implants (WhiteSky, BlueSky, Bredent, Germany) were inserted in the os frontale and analysed by histomorphometry. Cytotoxicity and SEM showed good biocompatibility in relation to the investigated implant materials. Histological results showed direct bone-implant contact of the implant surfaces. The zirconium implants showed a slight delay in osseointegration in terms of bone-implant contact as measured by histomorphometry (after 4 weeks, zirconium (59.3 ± 4.6%) versus titanium (64.1 ± 3.9%); after 12 weeks, zirconium (67.1 ± 2.3%) versus titanium (73.6 ± 3.2%). A statistically significant difference between the two groups was not observed. The results indicated similar biocompatibility and osseointegration for zirconium compared to titanium implants.

The new Baha implant: a prospective osseointegration study

OBJECTIVES

To assess stability of a new-design titanium implant (Cochlear Baha BAI300) in bone-anchored hearing aid (Baha) recipients over time.

STUDY DESIGN AND SETTING

Prospective case series with planned data collection at a tertiary care institution. Twelve patients who underwent Baha surgery over 12 months were analyzed.

SUBJECTS

All patients (3 children, age range 6-10 years, mean 7.7 years, median 7.3 years; 9 adults, age range 34-73 years, mean 52.8 years, median 48 years) underwent the 1-stage procedure following the standard Brånemark technique. In all procedures, the single-skin incision was applied.

METHODS

The stability of the implant was measured with implant stability quotient (ISQ) measurement tests. All patients were tested at surgery and every week after for 1 year. Wound-healing time, degree of soft tissue reactions around the abutment, and need for revision surgery were examined. Two-tailed Student t test and χ(2) for all comparisons were calculated; P < .05 values were considered significant.

RESULTS

The new implant showed a steep increase of ISQ values over the first 2 weeks and reached stable ISQ values 3 weeks after surgery. Complete skin healing time was obtained in 8 days on average (range, 7-12 days; median 7.6 days). Neither implant extrusion nor skin revision surgery was observed in our patients during the first year of follow-up.

CONCLUSIONS

This new implant revealed stability and fast integration. The data from the present study suggest the new implant may be suitable for early loading protocols.

Posttreatment quantification of patient experiences with full-arch implant treatment using a modification of the OHIP-14 questionnaire

Patient well-being is always the goal of rehabilitation of edentulism; however, evaluations of treatment success often overlook the patient's subjective feelings about comfort, function, speech, social image, social inhibitions, psychological discomfort, and/or disabilities. The purpose of this study was to assess these patient responses using an oral health questionnaire. To assess such feelings, a self-administered 20-question multiple-choice patient-reported Edentulous Patient Impact Questionnaire was developed, based upon the previously validated Oral Health Impact Profile patient-assessment tool. Responses were solicited from randomly selected patients treated with an implant-supported, fixed, immediately loaded full arch prosthesis. The questionnaires were completed by 250 patients. Of the respondents, 95% described themselves as being either extremely satisfied (74%) or satisfied (21%) with their new teeth, and 98% said they would definitely recommend similar treatment (88%) or consider recommending it (10%) to a friend or colleague. Based upon an oral health impact survey completed by 250 patients treated with full-arch implant-supported, immediately loaded fixed dental prostheses, it appears that patient satisfaction is high and that treated patients would generally be willing to recommend this treatment to others.

The All-on-Four Immediate Function Treatment Concept With NobelActive Implants: A Retrospective Study

The All-on-Four treatment concept provides patients with an immediately loaded fixed prosthesis supported by 4 implants. This single-center retrospective study evaluated the concept while using the NobelActive implant (Nobel Biocare, Gothenburg, Sweden). Seven hundred eight implants placed in 165 subjects demonstrated a cumulative survival rate of 99.6% (99.3% in maxilla and 100% in the mandible) for up to 29 months of loading. The definitive prosthesis survival rate was 100%.

Study of the osseointegration of dental implants placed with an adapted surgical technique

OBJECTIVE

To study the osseointegration of dental implants placed with a modified surgical technique in Beagle dogs and to compare it with the conventional method.

MATERIALS AND METHODS

Dental implants were placed bilaterally in the mandible of Beagle dogs using the press-fit as well as undersized implant bed preparation technique. Micro computer tomography (micro-CT) and histometric methods were used to analyze the bone implant contact and bone volume (BV) around the implants.

RESULTS

The bone-to-implant contact percentage (BIC: expressed as %), first BIC (1st BIC: expressed in mm), sulcus depth (SD: expressed in mm) and connective tissue thickness (CT: expressed in mm) were analyzed for both groups. The BIC percentage was significantly higher for the undersized installed implants (P=0.0118). Also, a significant difference existed between the undersized and press-fit installed implants for the first screw thread showing bone contact (P=0.0145). There were no significant differences in mucosal response (SD and CT) for both installation procedures. Also, no significant difference was found in the BV, as measured using micro-CT, between the implants placed with an undersized technique (59.3 ± 4.6) compared with the press-fit implants (56.6 ± 4.3).

CONCLUSION

From the observations of the study, it can be concluded that an undersized implant bed can enhance the implant-bone response.

The acceleration of implant osseointegration by liposomal Wnt3a

The strength of a Wnt-based strategy for tissue regeneration lies in the central role that Wnts play in healing. Tissue injury triggers local Wnt activation at the site of damage, and this Wnt signal is required for the repair and/or regeneration of almost all tissues including bone, neural tissues, myocardium, and epidermis. We developed a biologically based approach to create a transient elevation in Wnt signaling in peri-implant tissues, and in doing so, accelerated bone formation around the implant. Our subsequent molecular and cellular analyses provide mechanistic insights into the basis for this pro-osteogenic effect. Given the essential role of Wnt signaling in bone formation, this protein-based approach may have widespread application in implant osseointegration.

Loading protocols for mandibular implant overdentures: a systematic review with meta-analysis

BACKGROUND

Mandibular overdentures are a successful treatment option for the edentulous patients with long-term predictable outcomes, using conventional loading protocols. Currently, both early and immediate loading protocols for mandibular implant overdentures are prevalent in the literature.

PURPOSE

A systematic review and meta-analysis of the current published literature on comparative studies using conventional versus either early and/or immediate loading protocols for mandibular implant overdentures.

MATERIALS AND METHODS

The review was carried out in accordance with the QUOROM (Quality of Reporting of Meta-Analyses) guidelines. The PICO (Population, Intervention, Comparisons, Outcomes) format was used in conjunction with predefined inclusion criteria. A literature search of PubMed (1969-October 2008), EMBASE (1998-October 2008), the Cochrane Database of Systematic Reviews, and the Cochrane Controlled Trial Register was conducted. In addition, hand searching through refereed dental journals was also performed for the years 2000 to 2008. The meta-analysis was conducted by using the MIX software v.1.7 (Kitasato Clinical Research Center, Kanagawa, Japan).

RESULTS

A total of 191 studies were identified through the electronic search. After full-text screening and cross-matching with the predefined inclusion criteria, only 10 studies with a minimum follow-up of 2 years were eligible for inclusion in this review. Of the 10 included studies, seven have compared the outcome of conventional versus early loading of implants supporting mandibular overdentures. The remaining three studies, on the other hand, compared the outcome of conventional versus immediate loading. The meta-analysis revealed no significant difference in the outcome between conventional and either early (p = .72) or immediate (p = .08) loading of implants supporting mandibular implant overdentures.

CONCLUSIONS

Short-term outcomes of early or immediate loading protocols for mandibular implant overdentures achieved comparable success to conventional loading ones. No evidence was found of long-term studies to support or refute either early or immediate loading protocols for mandibular implant overdentures.

Histomorphologic and histomorphometric evaluation of various endosseous implant healing chamber configurations at early implantation times: a study in dogs

AIM

The objective of this study was to evaluate the early healing of endosseous implants presenting various healing chamber configurations in a beagle dog mandible model.

METHODS

The four premolars of 12 beagle dogs were extracted and allowed to heal for a period of 8 weeks. Implants allowing six different healing chamber configurations were placed in each dog (three per side, six configurations per dog). The animals were sacrificed after 3 and 5 weeks in vivo (n=6 per time in vivo), and the implants were non-decalcified processed to slides of approximately 30 microm thickness. Bone-to-implant contact (BIC) and bone area fraction occupied (BAFO) within the healing chamber were quantified. Statistical analysis was performed by a GLM ANOVA model at 5% significance level.

RESULTS

Osseointegration and healing with woven bone filling throughout all healing chambers was observed. Replacement of woven bone by lamellar bone showing primary osteonic structures was observed at 5 weeks. BIC was significantly affected by healing chamber configuration (P<0.001) and was not affected by time in vivo (P>0.42) at 3 and 5 weeks in vivo. BAFO was not affected by healing chamber configuration (P>0.14) however significantly increased over implantation time (P<0.001).

CONCLUSION

Regardless of healing chamber design and dimensions considered, healing allowed the devices osseointegration. However, healing chamber configuration significantly affected osseointegration measurable parameters such as BIC.

Which device is more accurate to determine the stability/mobility of dental implants? A human cadaver study

Non-invasive devices including resonance frequency (RF) analysis and mobility measuring (MM) damping capacity assessment are used to measure implant stability/mobility. The aims of the study were to compare the primary stability of implant inserted into extraction sockets by using RF with cable, RF wireless and new wireless MM device, to clarify the relation between these devices and to understand the correlations between peri-implant bone levels and implant stability. A total of 30 screw-type implants (3.75 x 11 and 4.2 x 11 mm) were inserted into extraction sockets of eight mandibular pre-molar regions of human cadavers. The primary stability of implants was measured by three devices after insertion. Peri-implant vertical defects were created in millimetre increments ranging between 0 and 5 mm, and stability/mobility of implants were analysed. At placement, the mean implant stability quotient of RF with cable, RF wireless and MM device values was 46 +/- 1, 57.8 +/- 9 and -5.4 +/- 1, respectively. Statistical correlations were demonstrated between these devices (P = 0.001). Statistically significant differences were presented for all peri-implant detects ranging between 0 and 5 mm for RF with cable and RF wireless at all increments. However, only a significant decrease was found between 0 and 1 mm defects, and 4 and 5 mm defects in MM device. Although RF with cable and RF wireless seem to be suitable to detect peri-implant bone loss around implants in 1 mm increments, the new MM device may not be suitable to detect the 1 mm peri-implant bone changes in human dried cadaver mandibles.